1. Field of the Invention
This invention relates generally to the field of multiple channel audio systems. More particularly, this invention relates to an apparatus for providing a surround sound system having multiple channels to provide a more realistic three dimensional sound which is particularly advantageous to theater applications such as home entertainment systems. Finally, this invention relates to an apparatus for privately enjoying realistic, three dimensional sound.
2. Background
Modern day stereo audio reproduction systems provide sound reproduction more realistic than monophonic systems because two soundfields are utilized to give the listener an impression closer to that of alive performance which generates sound from multiple sources located at multiple points in space relative to the listener. However, to more truly reproduce live performances, considerably more than two soundfields are needed.
In fact, low and high frequency sounds which are heard by a listener arrive via multiple paths. In addition to a direct, simultaneous arrival, high and low sounds often are reflected or bounced off walls and objects prior to arriving at the listener""s ears. Depending upon their source and line of transmission, sounds may be characterized as direct, reverberations, and indirect late reverberations which may be measured with digital computing equipment. The multiple arrival of sound causes perceptibly phase shifted signals.
There is therefore a need for stereo sound systems that reproduce direct sounds, reverberations, and indirect late reverberations. Recent stereo reproduction systems provide more realistic sound reproduction than ever before by utilizing multiple channels to separate low frequencies from high frequencies. Multiple channels in a surround sound(trademark) system may also separate and delay secondary sound features such as echo and reverberation, from primary sound features including voices and xe2x80x9cmid-rangexe2x80x9d tones. Additionally, even more channels can separate signals. The signals may be broadcast at varying angles relative to a listener to provide an effect of hearing different sounds from different directions.
Conventional surround sound(trademark) systems include a plurality of speakers distributed across the front of a room or theater, with three dimensional sound speakers located along each side of the room or theater. In such an arrangement, a viewing screen is located on or near a front wall. The front speakers include at least a left channel speaker and a right channel speaker. Other speakers may be included. For example, in an eight channel system, a sub-woofer for reproducing extreme lower frequency sounds, and center left and center right channel speakers are included. Left and right surround speakers are mounted on side walls or stands to produce the effect of surrounding the audience in the seating area. Encoded signals in a surround sound(trademark) system can be processed using the methods described in U.S. Pat. No. 5,642,423 assigned to Sony(trademark) Corporation, which is hereby incorporated by reference.
One of the problems associated with three dimensional sound technology is the amount of room such a system takes up. The complexity of the system requires speakers to be spaced around a room. When the side speakers are spaced a significant distance from the front speakers, sound separation is maximized. An even more realistic effect is provided when back speakers are provided a considerable distance from the front and side speakers. There is a need for a surround sound(trademark) system that uses very little room and yet provides realistic surround sound.
Another problem with home or theater three dimensional sound systems is the lack of a three dimensional sensation a listener feels if he or she is not positioned correctly relative to the speakers. A person positioned very close to some side or back speakers, and relatively far from other speakers, will not be able to perceive the entire effect of the sound separation. Accordingly, there is a need for a surround sound(trademark) system that allows a listener to freely roam throughout a room while still perceiving the effect of three dimensional sound.
Furthermore, conventional home surround sound(trademark) systems do not allow a person to listen in privacy. Everyone present in or near a room that is equipped with three dimensional sound speakers must hear whatever is being transmitted, regardless of whether they desire to listen. It is clear there is a need for a surround sounds(trademark) system capable of being listened to by as few as one person, even if other people are in the same room as the listener.
It is an object of the present invention to meet the above-described needs and others. Specifically, it is an object of the present invention to provide a surround sound(trademark) headphone system. Other objects and advantages of the present invention may be identified by reading the following detailed description, practicing the invention, or considering the appended claims.
To achieve these objects and others, an exemplary embodiment of the present invention may include: A stereo headphone set which includes a headset including left and right casings. The left casing may be positioned near or against a user""s left ear when in use, and the right casing may be positioned near or against the user""s right ear when in use. Two sets of speakers are attached to or housed within the casings. Each set of speakers may include one or more high frequency speakers producing higher frequency sounds than other speakers that are in the set. Each speaker in each set may be capable of receiving individual signals from separate channels.
The stereo headphone set may include an electrical device for separating one or more individual signals into two or more signals. The separation may result in one signal that transmits sounds of higher frequencies than those transmitted by remaining signals. In one embodiment of the invention, the separating device may be located directly on said headset. In another embodiment, the separating device may be located on a plug. The plug may be attached to the headset by a cord. The plug may be adapted to combine with and receive signals from a port located in a remote stereo sound system.
The stereo headphone set may include a delaying device for delaying at least one of said separated signals before it is transmitted to a speaker. The delayed signal may be channeled to one speaker, or set of speakers, while the signal that is not delayed may be channeled to other speakers. This separation and delay procedure produces an echo or reverberation effect for a listener when he or she hears the delayed signal or signals.
In a preferred embodiment of the invention, the user may use the headphones to listen to all sorts of transmitted sounds. If a user desires to listen to a recording or other sound transmission without using the surround sound, or echo features, a switch may be included allowing the user to switch between utilization of the separation device, utilization of the delaying device, and utilization of neither the separation device nor the delaying device. The switch may be located directly on the headset. The switch may also be located on a plug similar to that described above.
One of the speakers in each casing may be positioned closer to each of the user""s ear auricles than the remaining speakers. Arranging some speakers closer to the user""s ear auricles than other speakers allows secondary sounds such as echoes and background, while the user is still not distracted from the primary sounds coming from the speakers closer to his or her ear auricles. Also, if the speakers located farther from the user""s ear auricles are positioned in the casings near the hindmost or front portions of the user""s ear, the secondary sounds may seem to be coming from behind, or in front of the user. Similarly, if the secondary speakers are positioned in the casings near the top or bottom portions of the user""s ear, the secondary sounds may seem to be coming from above or below the user.
Some speakers may be positioned within the left and right auricles of the user""s ear. In such an embodiment, the headphones could be extremely lightweight, as the speakers located within the auricles of the user""s ear may be in casings that are supported in place by the ear auricles themselves.
The headphone system may also include separate volume controls, each volume control regulating the amplification of the sound coming from each of the speakers in each set. The volume controls may be included directly on the speaker casings, or on the headband portion of the headset. The controls for each speaker may also be remotely located relative to the headset, such as on a remote stereo sound system.
In another embodiment of the invention, a set of at least two chambers may be located in each casing. Each chamber is included to house an individual speaker. By individually housing speakers, each chamber may position the speaker. As a result, the speakers may direct sound toward the user""s ears.